The Replacement for Displacement

34.5K

Views

In this month’s editorial, the editor-in-chief makes the case for smaller, turbocharged engines that are quickly replacing larger naturally-aspirated ones to improve both performance and efficiency. It just may be the best of both worlds.

There's no replacement for displacement. It's an age-old axiom that muscle-car enthusiasts have been espousing for decades, opining that there's no better way to get power out of an engine than going for as many cubic inches as possible. Back when engines were primitive, that may have held true. And there's a certain level of truth to that still today, but it's no longer strictly the case. These days, carmakers are developing new powertrain technologies that aim to decrease the size of their engines while increasing both output and efficiency.

Arguably at the forefront of the Replacement for Displacement camp, somewhat ironically, is Ford. We say "ironically" because Ford has long championed big engines, slotting large-displacement V8s into anywhere it will fit. But the times they are a-changing, as Bob Dylan wrote at a time when muscle cars still ruled the road. Ford has been positively evangelical about its EcoBoost program. The idea is to replace cylinders and cubic inches with turbochargers and direct injection in order to yield as much (if not more) power and torque while decreasing the environmental impact of the engines in their cars. And it's been working wonders.

After replacing some of its V8s with a smaller 3.5-liter EcoBoost V6, Ford started downsizing other engines, too. V6s have gradually been replaced by a 2.0-liter EcoBoost inline-four, and after delivering results at the Nurburgring, Ford has begun slotting a miniscule one-liter, three-cylinder EcoBoost into European models and even the US-spec Fiesta. Who could have imagined that Ford would offer an three-pot in a market where it's known for twice the cylinder count? Of course Ford isn't the only automaker employing these technologies, and it's not just mass-market cars, either. Even high-performance automobiles have been getting in on the downsizing action.

BMW, for example, is replacing the V8 and V10 in its M3 and M5/M6 models with turbocharged six- and eight-cylinder engines, and power is only increasing. Audi has also dropped the V10 from its RS6 and S8 in favor of turbocharged V8s, and the benefit has not only been to fuel efficiency and emissions: with a lighter engine up front, weight balance has improved, and along with it handling. New developments like twin-charging, variable-vane and sequential turbos have also been designed to offset the dreaded turbo lag associated with larger spools, thereby providing better low-end response without sacrificing peak performance.

Even Maserati, which just revealed the new engines developed for the latest Quattroporte, has downsized its engines, but increased their output. While the outgoing QP was launched with a 4.2-liter V8 with 400 horsepower and a 4.7 with 425, the new model will be offered with a 3.0-liter V6 with 404 hp or a 3.8-liter V8 with 523, both made possible by direct injection and twin turbochargers. Bentley, for another example, has done the same, with a twin-turbo V8 exceeding earlier output figures from its W12. The list goes on and on, and will only stand to grow even longer with each passing year until we either find more oil or the internal-combustion engine goes the way of the dinosaurs whose fossils it burns.

Of course there will always be some enthusiasts for whom there will never be any replacement for displacement, and automakers will continue building cars to suit them for as long as regulations and public pressure will allow. Cars like the Ford Mustang and Chevrolet Corvette will always need to have V8s, but the next generation of both of these American sports cars are also expected to offer smaller turbocharged V6s. And if that's not a sign of the times, we quite frankly don't know what is.